Providers of telephony over IP networks may desire to increase revenue by providing more than one line (i.e., more than one telephone number) from corresponding multiple ports from a user device, such as a telephone modem that operates according to the PacketCable standard, for example. However, some customers may decide not to pay for more than one line to use for a fax machine, for example, due to cost. Therefore, there is a need in the art for a system and method for providing a lower cost line that supports facsimile transmissions (both send and receive operations) but does not support voice telephone calls.